Centrifugal bowl



' July 14, 1953 Filed March 7, 1950 Fla .1

G.J.STREZYNSKI CENTRIFUGAL BOWL 2 Sheets-Sheet 1 \/E N TO P /9 G50. tISTRE-zm' Sm Ida. llw

A RNEYJ secondary chamber.

Patented July 14, 1953 OFFICE CENTRIFUGAL BOWL George J. Strezynski, Poughkeepsie, N. Y., i assignor to The De Laval Separator Company, New York, N. Y., a corporation of New Jersey Application March '7, 1950, Serial No. 148,202

12 Claims. (01. sea-2s) This invention relates to centrifugal bowls and .has for its object the provision of an improved heretofore, because for some purposes they afiord certain advantages over single-chamber bowls. For example, when two liquids to be separated contain sludge, the latter can be separated from the mixture in a primary chamber of the bowl to prevent the sludge from interfering with the subsequent separation ofthe two liquids in the ondary chamber so that it does not clog the spaces between the conical discs in the separating zone of the secondary chamber, where the vtwo liquids are separated.

The prior centrifugal bowls of this type are not, however; entirely satisfactory, particularly with respect to obtaining a good separation of thetwo liquids in the secondary chamber. This isespecially so in cases Where one of the components of the material to. be separated is an oily substance. Thereason for this, I have found, is that the oily substance produces an emulsion in the primary chamber dueto rather violent agitation incident to feeding the mixture into such chamber, and it is practically impossible to obtain a good separation ofthe emulsion even between the discs in the secondary chamber.

According to the invention, such emulsification is avoided or greatly reducedby providing in the inner portion of the primary chamber a quiescent zone in which at least the more readily separable ,part of the oily component of the mixture can accumulate. More particularly, the bowl has an inlet passage for the material to be separated communicating with the inner portion of the primary chamber, and a flow-restricting member at the junction of this passage with the primary The sludge thus separated :maybe dischargedvfrom the outer part of the primary chamber into the outer part of the sectition between the primary and secondary chambers and into the inner portion of the secondary ,chamber, where it can join and be discharged with the light component separated in the latter chamber. The remainder of the mixture in the primary chamber is discharged separately into the secondary chamber from a zone or zones located outwardlyfrom the quiescent zone.

,By providing a quiescent zone in the primary chamber at the location described, a substantial part of the oily component, which is displaced inwardly in the primary chamber under the action of centrifugal force, will collect in this zone and be protected thereagainst the usual turbulence and agitation due to feeding the mixture into the primary chamber; In this way, the formation of the usual emulsion in the primary chamber is prevented to a great extent, so that the mixture passing into the spaces between the discs in the secondary chamber can be separated more efiectively than has been possible heretofore, in bowls of this type.

I Preferably, the partition between the two chambers includes the bottom disc of a stack oiconical separating discs in the intermediate ,zone of the secondary chamber; and sludge separated. in the primary chamber is discharged through peripheral slots in a nave of the bowl the outer parts of the discs, while additional material is discharged from an intermediate zone Fig. 2 is a horizontal sectional view of the primary chamber into distributing holes or openings in the medial portions of the discs. The sludge thus passes into the large diameter portion of the disc stack where the disc interspaces have relatively large throughflow areas leading to the outer zone of the bowl, so that the sludge is delivered evenly to this outer zone bowl periphery, andthe components separated between the discs may be discharged through separate outlets located at different radii nearer the bowl axis.

For a better understanding of the invention, reference may be had to the accompanying drawings, in which Fig. l is a vertical sectional view of part of a preferred formof the new bowl, and

on the line 2-,2 in Fig. 1.

Referring to the drawings, the bowl comprises i a cylindrical shell I 0 and a bowl top H held clearance.

' zone of the secondary chamber. l9 rests at its inner portion upon the expanded zone of the primary chamber. -peripheries, the discs are formed with circumfertogether by a nut l2. A central tubular shaft 13 overlies and is supported by a nave I4 secured to the bottom of the shell H]. A spindle l5 has at its upper portion a tapered fit in the central part of the nave l4 and serves to support and rotate the bowl on its axis.

The interior of the bowl is divided into a primary separating chamber A and a secondary separating chamber B, the latter extending above and outwardly of the primary chamber. The material to be separated is fed into the tubular shaft [3 by means of a stationary tube I6 extending into the upper part of this shaft. The tubular shaft [3 constitutes means forming an annular inlet passage [3a through whichthe material to be separated passes downwardly and outwardly into the inner portion of the primary chamber A, the inlet passage 13a surrounding a reduced part of the nave M which extends into the lower portion of the tubular shaft with a The inlet passage contains radial wings 17 extending inwardly from the tubular shaft toward the bowl axis and engaging the have M to provide support for the tubular shaft.

The-primary and secondary chambers A and B are separated from each other by partition means including the lower expanded part [31) of the tubular shaft and the bottom disc of a stack of conical separating discs IS in the intermediate The bottom disc part |3b of the tubular shaft and at its outer portion on the periphery of the nave l4 and an inclined inner surface Illa of the bowl shell. The primary chamber is thus defined by the bottom disc, the nave l4 and the lower part of the-tubular shaft 13. The medial portions of the disc are formed with circumferentially spaced, vertically aligned distribution holes 19a into which material from an intermediate zone of the primary chamber is delivered through hollow tubes 20 secured to the bottom disc around the holes 19a. The tubes 20 extend inwardly into the intermediate Near their outer entially spaced sets of vertically aligned distribution holes [9b which overlieslots- Ma in the outer part of the nave M. The slots Ma'extendoutcharging sludge from this chamber into the disc 3 interspaces near the outer zone of the secondary chamber.

The separated sludge is discharged from the secondary chamber B through circumferentially spaced outlets 10b in the bowl periphery. These outlets Ifib, as shown, are controlled by valves 22 of the type disclosed in my Patent No. 2,141,025,

dated December 20, 1938. A top disc 23 forms with the bowl top I l a series of circumferentially spaced discharge passages Ha leading upwardly andv inwardly from a region ofthe secondary chamber located just outside the discs IS. The

. passages I la serve to discharge an intermediate component, separated between the discs l9, from the secondary chamber. through a bowl outlet l lb. The light component separated between the discs is displaced inwardly into verticalpassages 24 at the inner edges of the discs, and is then discharged upwardly through the neck of the top disc 23, which forms a bowl outlet 23a.

The wings l1 in the tubular shaft extend downs wardly into the inner portion of the primary chamber A, where they are notched as shown at lla. At. the junction of the inlet passage 13a,

' wardly and downwardly from the. outer zone of 7 the primary. chamber, and form passages fordiswith the primary chamber A, there is a flowrestricting member 26 in the form of a ring surrounding the nave I l. The ring 26 is secured by screws 26a to generally horizontal edges of the wings I1 formed by the notches Ha, the inner part of the ring being 'thus held against the fiat bottom of an upwardly tapering collar 21 closely surrounding the nave and engaging inclined inner edges of the wings H. The ring 26 forms with the nave l4 an annular quiescent zone 28 extending inwardly toward the bowl axis from the junction between inlet passage Ba and the primary chamber. At its outer edge, the ring 26 forms the inner confine of an annular orifice 29 through which the inlet passage opens into the primary chamber, the orifice being located outwardly from the quiescent zone 28. Hollow tubes 31) extend inwardly from the tubular shaft l3 beyond the orifice 29 and into the interior of the quiescent zone. These tubes form passages through which a light component is discharged outwardly from the zone 28 through the tubular shaft I3 and into the vertical passages 24. in the secondary chamber, where it joins the light component separated between the discs I9 and is finally discharged through the bowl outlet 23a. It will be observed that the lower wall of ring 26 extends radially inward from the orifice 29 through a substantially greater distance than the width of this orifice, so that the ring forms a quiescent zone 28 of sufiicient width to receive the light component of the feed and maintain it substantially, free of the turbulence incident to passage of the feed through orifice 29.

The operation of the bowl will be described in connection with the. separation of butter oil, as the bowl may beused to particular advantage for this purpose. The milk product is fed from tube I5 through the inlet passage l3a, where the wings ll impart rotation to the material so that it is forced centrifugally against the inner wall of tubular shaft [3. As the material enters the primary chamber A the ring 26 restricts the flow so that the material enters this chamber outside the quiescent zone 28, by way of the orifice 29. In thechamber A, the product is subjected to a primary centrifugal separation so that it is separated into sludge or curds as a heavy phase, skim milk (and some entrained curds) as an intermediate phase, and oil as a light phase. Although thisseparation is not complete in the primary chamber, a substantial part of the oil is displaced inwardly'into the quiescent zone 28 under ring 26, where the oil is protected against the usual turbulence and agitation incident to feeding the material into the primary chamber. That is, the incoming material, being confined by the orifice 29, flows through the spaces between the tubes 30 at their outer portions adjacent the tubular shaft 13 and therefore is prevented from causing any substantial agitation in the zone 28. Accordingly, the oil or fat separated in the primary chamber isdischarged through the tubes 30 into the inner zone 24 of the secondary chamber, without being subjected to emulsification due to agitation bythe incoming feed stream.

The curds separated in the primary chamber are discharged through the slots [4a into the outer distribution holes l9b of the discs in the secondary chamber. Since the disc interspaces at this outer region of the discs have relatively large throughfiow areas, due to their greater circumferential extent, the curds may pass freely and evenly into the outer zone of the secondary chamber,- from which they are dischargedthrough the valved outlets lllb. The intermediate phase separated in the primary chamber, consisting mostly of skim milk together with some entrained oil and fine curds, is discharged through tubes 20 into the distribution holes 19a of the discs in the secondary chamber. In the disc interspaces, a more complete separation occurs, the skim milk and any entrained curds passing outwardly along the lower surfaces of the discs and into the outer zone of the secondary chamber, from which the skim milk is discharged through passages I I a and the curds are discharged through outlets [b. The oil separated between the discs is displaced inwardly along the upper surfaces of the discs and into the vertical passages or inner zone 24 of the secondary chamber, where it picks up the oil from tubes 30 and is discharged through outlet 23a.

By arranging the outer distribution holes I911 of the discs so that they directly overlie the slots Ha in the nave, the initially separated curds discharged from the outer part of primary chamber ,A are not only allowed to pass to the outer zone of the secondary chamber B without clogging, as previously mentioned, but are also subjected to a secondary separation between the discs at a region of relatively high centrifugal force. In this way, oil entrained in the curd phase from the primary chamber is separated between the discs and displaced inwardly so that it joins the oil discharging through passages 24.

I claim:

1. In a rotatable centrifugal bowl for separating materials into components of different specific gravities and having partition means dividing the bowl interior into primary and secondary separating chambers, the partition means having an opening displaced outwardly from the inner portion of the primary chamber for. delivering into the secondary chamber material partially separated in the primary chamber, the secondary chamber having outlets at different radii from the rotation axis of the bowl for discharging separated components of the material, the combination of means forming an inlet passage communicating with the inner portion of the primary chamber for delivering thereto the material to be separated, a flow-restricting member supported within said passage means at the junction of the inlet passage with the primary chamber and having a free outer edge forming with said passage means, at said junction, the inner confine of an orifice through which the material to be separated passes into the inner portion of the primary chamber, said member also having a generally horizontal wall extending from the orifice inward toward the rotation axis of the bowl through a substantial greater distance than the width of said orifice and partly defining, at

'the outlet side of the orifice, a quiescent zone of the primary chamber located between said junction and said axis, and a hollow tube extending from the partition means inwardly beyond said free edge and into the quiescent zone, the tube forming a light component passage leading outwardly from said zone through the partition means into the inner portion of the secondary chamber.

2. The combination according to claim 1, in which said passage means is a tubular shaft rotatable with the bowl, the flow-restricting member being a ring mounted in said shaft and overlying the quiescent zone.

3. The combination according to claim 1, comprising also a radial wing mounted in the inlet passage and rotatable with the bowl to impart rotation to the material passing through the passage, the wing having a generally horizontal edge at said junction of the inlet passage with the primary chamber, and means for securing the flow-restricting-member to said horizontal edge.

4.In a rotatable centrifugal bowl for separating materials into components of different specific gravities and having partition means dividing the bowl interior into primary and secondary separating chambers, the partition means having an opening displaced outwardly from the inner portion of the primary chamber for delivering into the secondary chamber material partially separated in the primary chamber, the secondary chamber having outlets at different radii from the rotation axis of the bowl for discharging separated components of the material, the combination of a tubular shaft in the bowl rotatable therewith and forming an inlet passage communicating with the inner portion of the primary chamber for delivering thereto the material to be separated, a nave in the bowl partly defining the primary chamber and extending into the tubular shaft with a clearance, an annular flow-restricting member surrounding the nave at the junction of the inlet passage with the primary chamber and having a free outer edge forming with the tubular shaft, at said junction, the inner confine of an annular orifice through which the material to be separated passes into the inner portion of the primary chamber, said member also having a generally horizontal wall extending from the orifice inwardly toward the rotation axis of the bowl through a substantially greater disstance than the width of said orifice and defining with the have, at the outlet side of the orifice, a quiescent zone of the primary chamber located between said junction and said axis, and hollow tubes spaced circumferentially around the tubular shaft and extending inwardly therefrom into the quiescent zone, the tubes forming light component passages leading outwardly from Within said zone and through the tubular shaft into the inner portion of the secondary chamber.

5. The combination according to claim 4, comprising also radial wings in the tubular shaft and having generally horizontal shoulders at said junction, and means for securing the flow-restricting member to said shoulders.

6. The combinationaccording toclaim 4, in which the nave has slots extending outwardly from the primary chamber toward the bowl periphery, said partition means including a bottom disc resting upon the nave and having openings overlying the slots, the slots and openings forming a heavy component passage leading from the outer portion of the primary chamber to the outer portion of the secondary chamber.

7. In a rotatable centrifugal bowl for separating materials into components of different specific gravities and having partition means dividing the bowl interior into primary and secondary separating chambers, the partition means having an opening displaced outwardly from the inner portion of the primary chamber for delivering into the secondary chamber material partially separated in the primary chamber, the secondary chamber having outlets at diiferent radii from the rotation axis of the bowl for discharging separated components of the material, the combination of a tubular shaft in the bowl rotatable therewith and forming an inlet passage communicating with the inner portion of the primary chamber for delivering thereto the material to be separated, a have in the bowl partly defining the primary chamber and extending into the tubular shaft with a clearance, and a stack of conical separating discs in the secondary chamber and including a bottom disc forming part ofsaid partition means, the outer part of the bottom disc resting on the have and the inner part of the bottom disc resting upon the tubular shaft, the outer part of the nave having slots extending outwardly from the primary chamber, the discs having spaced sets of vertically aligned openings overlying an intermediate zone of the primary chamber, and also having spaced sets of vertically aligned openings overlying said slots.

' 8. The combination according to claim 7, comprising also a hollow tube secured to the bottom disc around each of said first openings therein and extending into said intermediate zone of the primary chamber.

9. The combination according to claim '7, comprising also hollow tubes extending inwardly from the tubular shaft into the inner portion of the primary chamber and forming. light component passages leading outwardly through said shaft into the inner portion of the secondary chamber, the discs having inner edges lying outside and opposite the outer ends of said last pas sages'. f

10. The combination according to claim '7,

comprising also hollow tubes extending inwardly from the tubular shaft into the inner portion of .the primary chamber and forming light component passages leading outwardly through said shaft into the inner portion of the secondary chamber, the discs having inner edges lying outside and opposite the outer ends of said last passages; and a generally horizontal ring at the junction of said inlet passage with the primary chamber and defining with the have a quiescent zone at the inner portion of the primary chamber, the ring overlying the inner end portion of said tubes and forming at its outer edge the inner confine of an annular orifice at said junction.

11. In a rotatable centrifugal bowl for separatingmaterials into components of different specific gravities and having partition means dividing the bowl interior into primary and secondary separating chambers, the partition means having an opening displaced outwardly from the inner a free outer edge forming with said passage means,

at said junction, the inner confine of an orifice through which the material to be separated passes into the inner portion of the primary'chamber, said member also having a generally horizontal ,wall extending fromithe orifice inward toward the'rotation axis of the bowl and partly defining, at the outlet side of the orifice, a quiescent zone of substantial width to receive the light component 'ofthe material and maintain it substantially free of the turbulence incident to passage of the material through the orifice, and a hollow tube extending from the partition means inward beyond. saidv free. edge and. into the quiescent zone, the tube forming a light component passage leading outward'from said zone into the inner portion of the secondary chamber.

12. A centrifugal bowl for separating materials into components of different specific gravities, which comprises a rotary bowl shell, partition means in the shell dividing the bowl interior into primary and secondary separating chambers, the secondary chamber having outlets at different radii from the rotation axis oi? the bowl for discharging separated components of the material, the partition means forming heavy and intermediate'component passages leading from the outer and intermediate parts of the primary chamber, respectively, to corresponding parts of the secondary chamber, means forming an inlet passage communicating with the inner portion of the primary chamber for delivering thereto the material to be separated', a member supported within said passage means at the junction of the inlet passage with the primary chamber and having a free outer edge forming with said passage means, at said junction, the inner confine of an orifice through which the material to be separated passes into the inner portion of the primary chamber, said member also having a generally horizontal wall extending from the orifice inward toward the rotation axis of the bowl and partly defining, at the outlet side of the orifice, a quiescent zone of substantial Width to receive the light component of the material and maintain it substantially free of the turbulence incident to passage-of the material through the orifice, and a hollow tube extending from the partition means inward beyond said free edge and into the quiescent zone, the tube forming a light component passage leading outward from said zone into the inner portion of the secondary chamber.

GEORGE; J. STREZYNSKI.

References Cited in the file of this patent UNITED STATES PATENTS France June 3, 1932 

